Passenger services begin on Tianjin Metro Line 4 Northern Section, China July 9, 2025 | Asia Pacific News, News Passenger services have commenced on the Northern Section of Line 4 of Tianjin Metro. The section spans 19.98 km and covers 16 stations (all underground). The section has been developed in the public–... This content is available to only subscribers. Username or E-mail Password Remember Me Forgot Password